Measurement Lecture 4

Bulk Checking

• After measuring and billing all available drawings, the next step involves preparation of the BQ which may contain over 1,000 items for typical building projects.
• As a QS it is impossible to check every quantity in BQ.
• Before the Bill of Quantities (BQ) is issued to tenderers, it undergoes a bulk checking process to ensure accuracy and eliminate major errors.
• Experienced staff members familiar with the project's nature and the Standard Method of Measurement (SMM) conduct this check.
• People who prepare the BQ should not be checking the BQ.
• Bulk checking should be expedite by simple forms and the records kept in the measurement file.
• The check should cover the following:
• Items involving large quantities or of major cost
• Coverage of items that significantly impact cost should align with design needs and drawings
• Squaring, abstracting, and billing of all items should undergo independent verification
• Possible errors in BQ include:
• Incorrect transferring or billing
• Typing errors
• Arithmetical errors
• The errors mentioned above are common.
• Bulk checking identifies gross errors in billed quantities caused by measurement or during transfer and billing in order to correct before tendering.
• Pareto principle (80/20 Rule) states that for many events, 80% of the effects come from 20% of the causes
• 80% of a company's revenue comes from 20% of its customers
• Historically, 80% of wealth in Italy was held by 20% of the population
• Following this principle, 80% of construction cost comes from 20% of items in BQ.
• Important relationships to check between items in BQ include:
• Concrete Volume (Wall) / Thickness of Wall = Wall Area
• Weight of Rebar = Volume of Concrete x Steel Ratio
• Typical Steel Ratio is around 200 kg / m³
• There are many relationships that need checking
• Wall finishes related to wall areas
• Tiled area matching screed area
• Plastered area matching painted area
• Excavation = Backfilling + Filling + Cart Away
• For example, if excavation volume is larger than backfilling/filling volume, it is a bulk check

Bulk Checking (HKIS 2014)

• Apply ratios from slide 8, which include relationships between:
• Formwork area and wall areas in concrete volume.
• Concrete Volume (Wall) / Thickness of Wall = Wall Area
• Rebar to concrete ratios.
• Weight of Rebar = Volume of Concrete x Steel Ratio
• Wall finishes and wall areas
• Tiled area matching screed area
• Plastered area matching painted area

BQ Terminology and Pricing

• Important terms in BQ are Preliminaries, Preambles, Specification, Prime Cost (PC), Provisional Sums (PS), and Dayworks.

• Preliminaries refer to project administration and site equipment needed, but not part of the work.

• Examples include temporary works, hoarding, office overheads, insurance, and as-built drawings.

• Preliminaries can be time or work related.

• The preliminaries section is priced by contractor's estimator and has 3 parts:

• Preliminary Particulars provides project introductory information including names of the employer, architect, and QS.

• It also includes a description of works, location, and division of work sections.

• Conditions of Contract states the form of contract with a schedule of clause headings that includes amendments and deletions.

• Examples include HKIA Standard Form of Contract with quantities to be used and clause 1: Main contractor's obligations.

• General Matters includes a list of unmeasurable items like working hours, plant tools, sheds, insurances, and hoardings.

• The preamble is an introduction to each trade in bills of quantities and includes details of measurement rules, particularly deviations from HKSMM4

• Hong Kong building measurement relies on HKSMM4 to standardize measurement practices.

• The QS should measure according to HKSMM4, but can change measurement methods if a preamble clause states the changes.

• Specifications are written by designers and describe the quality of materials, workmanship standards, and required tests.

• These are contract documents read in relation to drawings and BQ that give detailed information on trade steps and backup clauses.

• Specifications dictate the Quality of Work

• Job descriptions in specifications are written in terms of methods of performance level required to be used, or a direct use of trade names;

• In some cases, designers will have a standard specification. In others, there will be a special design that requires a specification outside of the general one.

• For a particular project with special requirements the architect may specify 'All roofing 30mm thick in 3 coats asphalt

• The QS is required to include all differences to the General Specification in the Particular Specification (PS). PS > GS

• Prime Cost and Provisional Sums are normally included in a section near the end of the BQ;

• Prime Cost(PC) is defined as a 'a sum in BQ is for a price that is stated. This is so materials to be obtained from a nominated supplier for fix only

• The contractor is reimbursed the amount to be paid, plus an allowance for profit, and keeps any discount allowed for prompt settlement of accounts

• A separate agreement may be needed on attendance if a PC is used.

• PC Sum included in BQ for Nominated subcontractors and suppliers.

  • Nominated subcontractors are required to pay architect instructions and client payments via main contractor.
  • The PC sum covers delivery costs, while labor costs are measured separately.

• Nominated Subcontractors are subcontractors chosen by designer and have to undertake specialist works for : piling, cladding, electrical , mechanical , lift and fire services

  • Can be specified, non specified
  • Profit = Main contractor pricing as a percentage of PC
  • Attendance= Main contractor pricing as a lump sum for attending.
    • Provide water, electricity, storage facilities and use of main contractors toilets and hub -Nominated suppliers who deliver, To site by nominated supplier & ADD Profit •Nominated supplier (PC Sum) =Cost for delivery •Fix only Item - for Labour costs

• Provisional sum = An amount of money mentioned in BQ to provide for items or work for which an exact price cannot be obtained or which are not clearly foreseen and will be subject to re-measurement

• Most used when design incomplete •The consultant QS will need to deduct the PS included in the BQ and re-measure and value the work under HKIA Standard Form of Contract Clause 11. •The monetary amount for PC Sums for nominated subcontractors and suppliers and Provisional Sums is usually estimated by the QS who will base the sum ON previous projects or use approximate quantities

• Dayworks are a payment method for work that involves agreement between clerks and contractor on work hours, which are used for correcting mistakes that the contractor is not at fault for.

• The contractor get's paid if the contractor provide a day work sheet that is signed by the clerk work of the work The contractor reimbursement is based of his expenses in labour and materials agreed on, which has overage expenses along with very expensive overheads Unit rates in BQ should be used whenever you can, but work is usually only evaluated if variation is Daywork basis

• If a architect issues a Variation by mistake, contractor require to go back to fix this issue and contractor will need payment on daywork basis

• Contactor need to pay : for the labour

  • Add profit and overhead percentage : to make for money for materials

Comparison of Pricing Documents

• Pricing documents include Bills of Firm Quantities, Bills of Approximate Quantities, Schedule of Rates, and a Drawing and Specification

• Cost certainty and control depends a lot on preparing tender documents.

• Bills of firmed quantities is the primary tool that is used in medium to large building contracts

  • The "lump some contract" is what Bill of firm quantities are used in.
  • Only Provisional quantities, provisional sums and PC are adjusted to at stage
  • Firm quantities : Both description and quantity known Rate : Binding, QTY:Binding E.G Ex tr strg from EG Egl ne 1.50m dp
    • Provisional quantities : Description know, quantity unknown QTY: Unknown E.G Ex tr strg from EG Egl ne 1.50m dp (PROVISIONAL)

• Bill of firm quantities has the following advantages -Cost certainty is high, -Excellent comparison ( because vendors are all buying the same thing) -Basis for management and evaluating of VARIATION ( Interim value of the BQ) -Reduction = Cost of design team needs to have prepare -Low risk and slow for the tendering environmen -Contractor and Vendor understands what he is buying

• Bill of firm disadvantages -Cost in preparation is much • For the level of cost certainty promised by this procurement methodology to be delivered, the design must have evolved before preparation of the BQ is started. • Errors in the tender documents are normally required to be corrected at the client's cost. • Pre-contract phase of procurement is lengthy compared to other procurement methods and so often leads to a later start on site. • Risk is generally dependent upon status of design at time of document preparation and therefore can mean that the Client can bear more risk if Design is not largely completed and therefore do not fully represent the final design or constructed solution.

• Bill of Approximate quantities = Civil Engineering Projects, apricing document used to measurement - This measurement means that all quantities, all sums adjust at the final account stage -Advantages of bills of approximate quantities, -Allows a earlier starts on site to be enable than other bill documents - Allows early appointment of a contractor and access buildy
  - - Can incorporate Design and Build and Performance Specified works if required •Bill of approximately quantities . DO NOT estabilsh a firm cost, -Less price certain - The design is calculatd to be avaliabel with remeasurements - The client proceeds to constructtion - due to the means of tenders

• Schedule of rates

  • No exact quantities
  • It give a scale that is description of each sort of work to be done, but no exact quanties,

• The bidders have to unit price for the items, and measure to get the final price

• Mainly for maintenace contract . Term contract - Schedule rates ; cause the contract last a specific priord of TIME term i;e two years

• Specifations of Drawing -Contractor is chosen based on lump some bid that details specifation document - Provisional allowances ,

• Measurement Q are prepared by the Tenderer enable to provde an exact price for the work - This needs of described and defined if the the inviters would not have the tender document - Specifation and Dwgs are appropiate for smaller project , I.E House extenstion

• Advanatage associated with S&d document - The lump is fimr :subject -Variation - Client risk is avoided, contacotr prepares it.

• Disadvanagt - Not easily comparable with Bills of QTY s - It has to advance to order - Smaller building works are required In HK, incompleted design and lack of time in preparing equals incomplete quantities , which is wrong. The client is charged as a results

Risk Assessment

• The question is risk failry apportioned between the client and contractor
• Clients are at a lower risk than constractor
• If a client had bill of quantity it would mean less risk , if the client takes the risk there will be a PC Sum
• Is a contract with DOMESTIC OR NOminated : DOMESTIC The more PC sums included in Bills of quantities : More risk that client takes It can cost more and or cause delay for material and labor ( if the nominated supplies delay, may be EOT may be ask if client does not like the job)
• There and extra expense in preparing and documentation

How to use SUM, - Important to know Why than are PC sums so commently used in hongkong - Is for fast tracking design the fast tracking. - They can deside in the architect of whick finishes are to be used. - To finish can be m,easure

Item Descriptions

• Has a applicable sections - to measure stanards

• Has item size

• Has item name/ quality ,if any

• Work imposed to the item concerned (twice bent/ timber) Methods to installation of fizing Sources to information ( 8milimiters) Example manufactures name is known - Meaure in full - with a Flush ddorr manufacturers is to provide only PC sums for only internal door

• PC sum for internal

• Measure fix internal door- and
  Componant organtes from maufcatucter from alttername

• The artchitects

  • That the Componatn for the name supplier measure in full and stated suppliers

2. Purpose made companants design by architext and architect will privde that that is detailed

3. Measurements in post is the measurmens if works that is complete. That is the measurement in to vaule - that is the cortafiy cortars monthly statements
4. Any estaminated sums to the opinons-

That has so there is large overpayments you should never attenpt to do this

Inlump sum and with firms BQ with Contract which the quananties container In remeusement ,

• all items in BQ- be mesaure that is the that bais.
• Inlump sum and with firms BQ with Contract which the quananties container

In remeusement ,

• all items in BQ- be mesaure that is the that bais.

individual assinment. 6 - forms Tutorial 4 10 min Question make recommednations of the siatuartion

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Questions cover construction preliminaries, bill of quantities (BQ) bulk checking, and contract conditions. Topics include the purpose of preliminaries, the importance of preliminary particulars, BQ checks, and the role of the 'preamble'. Also addresses schedule of clause headings.